1. Field of the Invention
This invention generally relates to a parking brake device, more particularly to an electrical vehicle parking brake device for controlling braking force for wheels by the driving power of a motor which is transmitted by way of a gear mechanism and a cable.
2. Description of the Related Art
Conventionally, with respect to an electrical vehicle parking brake device, technology in which a cable of a parking brake is pulled using the driving power of the motor so as to cause suitable braking force at the time of functioning is proposed. For example, in the U.S. Pat. No. 6,213,259, the electrical vehicle parking brake device, which includes a moving screw turning by the driving power of the motor and pulls the cable directly due to rotation of the moving screw as well as a nut side member of the moving screw is connected to the cable, is disclosed.
However, the above-mentioned conventional electrical vehicle parking brake device requires a length in the axial direction longer than a length of adding allowance to a maximum stroke of the cable as well as a moving screw and a nut side member Thus, the whole electrical vehicle parking brake device requires a length of adding allowance to the length at least two times as long as the maximum stroke of the cable for only the moving screw and a mechanical portion of the nut side member, and further increases a space for mounting in a vehicle.
Therefore, the present invention is invented in view of the above-mentioned backgrounds. At the time of parking the vehicle, in the electrical vehicle parking brake device for controlling the braking power for wheels by the driving power which is transmitted by way of the cable, the technical purpose of the present invention is to provide an electrical vehicle parking brake device in which the size thereof can be reduced in the cable axial direction and the degree of freedom of mounting in the vehicle can be increased.
It is an object of the present invention to provide an improved electrical vehicle parking brake device which pertains to reduce the cable axial direction.
In order to achieve the above-mentioned object, the present invention is characterized in that, in an electrical vehicle parking brake device for controlling braking force to a wheel by driving power of a motor transmitted by way of a gear mechanism and a cable, an end gear series of the gear mechanism includes a differential gear mechanism and winds up the cable in a circular way.